Knitting machine jack holder



Filed May 4, 1948 Patented Jan. 1, 1952 KNITTING MACHINE JACK HOLDER Jaroslav Vclavk, Zlin, Czechoslovakia, assigner to Bata, narodn podnk, Zlin, Czechoslovakia Application Maya 1948, serial No. 25,066 In CzechoslovakiaMay 8, 1947 4 Claims. 1

The present invention relates to Cotton knitting machines and more particularly .to a device in Cotton lknitting machines for holdingthe jacks and ,sinkers in their sinking position by means of va. spring `carrying bar or comb upon termination of the `sinking operation.

In Cotton knitting machines the sinking of the threads is eiected by means of jacks acting upon the sinkers. The jacks are controlled by a slurcock which travels `at high speed over the backs of the jacks. After a certain time the jacks become distorted due to the high lateral pressure exerted on the same by the slurcock; especially at. the high speeds of operation of the modern knitting machines. This lateral pressure, which becomes still `higherduring the end phase of the sinking movement, 4makes practically impossible any further increase of the speed of operation. This is a great disadvantage ,since otherwise the machine `could Vbe driven at a higher speed. The lateral pressure of the jacks makes the same unsuitable yfor further use after expiration of ,a certain time `so that frequent replacement of the jacks and as a consequence, losses of time and output .are unavoidable.

It has been proposed to use spring carrying bars` or combs in Cotton knitting machines for holding the jacks and sinkers in their sinking position. `In the usual types of Cotton knitting machines the springs are arranged underneath the slurcock in a position `in which during the sinking operation they exert pressure against corresponding projections provided on the jacks and also located underneath the slurcock. In such constructions the energy required for exerting the spring pressure on the projections provided at a low level on the jacks is very considerably dueto the large distance between the points of engagement Aof the springs and the points where the jacks are'pressed against the -sinkers so that the: springs and the projections on the jacks are 4subjected to considerable stresses and as a consequence wear off rapidly. However, even in the case of a very limited fatigue or wear of a single spring or `oi' a jack projection, the end position of the corresponding jack upon termination of the sinking movement is not secured suiliciently and the corresponding sinker may rebound from the sinker vabutment under the influence of the tension in the meshes so that as a result longitudinal .stripes will appear in the knitted fabric. In this arrangement the jack controlled by the slurcock is subjected to spring load during the whole lperiod of rocking whereby an increased resistance and undesirable lateral pressure between the slurcock and the jack arise. This lateral pres sure increases with the speed and 'the degree of `flneness of the machinev (more steeply curved sinking faces on the slurcocks), whereby unfavourable conditions for the operation of this mechanism arise resulting in wear and tear of the jacks and in certain cases also of the springs which then are to be replaced frequently by fresh ones in order to avoid defective knitting of the stockings. Moreover the alternating lateral pressures result in wear of the slurcock carrier which travels along the jack bar. Another disadvantage consists in the bad access to the spring bars or combs located underneath the slurcocks so that it is diicult to assemble and adjust these bars or combs.

The primary objects of the invention are to provide a jack and spring construction in which the springs are positioned to engage a cooperating face on the jacks toward the end of the motion of the `jacks to sinker advancing position to assist the finalmovement and effectively retain the jacks and `sinkers in advanced position and further to provide means for relieving the pressure of the springs onthe jacks so as to remove any frictional drag 'between springs and jacks during the major'portion of the movement of the latter.

These objects are accomplished by mounting the spring bar above the path of the slurcock with ythe springs extending toward the jacks and providing on the back of the jacks a projection having a -steeply inclined face engageable by they ends of the springs only after the jacks have shifted through the major portion of their path of travel to snker advancing position. In addition, the relief -of frictional drag on the jacks is accomplished 'by providing a spring lifting member, preferably in the form of a roller carried by the slurcock carrier `and positioned so as to lift the jack springs successively in coordination with engagement of the jacks by the slurcock so that the springs are held out of engagement with jacks -until just before completion of their motion,the springsupon release dropping down on the inclined face of the projection to assist in the flnalmotion -of 4the jacksvand thereafter to retain 4them and the sinkers against retraction due to the Atension of the thread. The roller is mounted on a `switch vmount and means are provided'to switch it into correct operative relation with respect tothe advancing or working face of the slurcock as each pass is completed.

The accompanying drawing shows by way of example an embodiment of the invention.

Fig. l is a side view in section showing the spring carrying bar or comb and the jack head in position `after termination of the movement of the jack andsinker to sinking position;

'Fig, t2 is a fragmentary plan View showing the action of the slurcock on the sinkers;

Fig3isa Asectional view on the line 3-3 of Eig. l and is. related to Fig. 2 to show the coordinated laction vof the spring lifting roller and the Ycarri lface o'f the slurcock;`

Fig. 4 is a partial side view showing the inoperative position of the springs with the jacks in position `just 'prior to the back stroke of the Vcatch bar;

Fig. 5 is a partial side view illustrating the action of the spring lifting roller vduring the sinking operation, and

Fig. 6 is a fragmentary detail illustrating the engagement of the spring end with the jack as the latter approaches the end of its travel to sinking position.

Referring to Fig. 1 of the drawing the references A, B denote jacks I mounted pivotally on a rod 2 and acting for a limited time on sinkers 3. Rocking movement is imparted to the jacks by means of a slurcock 4 which is fastened in a carrier 5 and travels over the backs of the jacks in the direction of the needle row. Each jack is provided with a projection 6 having an inclined face I co-op-erating with the free end S of a spring 9, the other end of the spring being fastened in the spring carrying bar or comb Iii. The spring carrying bar or comb is mountedin ,2. manner known per se between the side plates I i of the jack head I2. Rocking movement is irnparted to the spring bar or comb I in a Inanner known per se by a lever system I3, Hl and a roller (not shown) from a cam (also not shown) on the main shaft of the machine. The slurcock carrier has fastened thereon a, holder l5 carrying a lever I1 mounted pivotally about a pin IB (Fig. 3) on the holder. The lever Il carries on its one end a, freely rotatable roller: I8 having a, rounded periphery which acts for a time, and successively, on the stems of the springs 9. The end positions ofthe lever I'I and roller I8 are determined by a stop pin or screw I9 fastened in the holder I5. The lever I1 and roller I8 are switched over automatically, before the end of the path of the slurcock 4 along the edge of the needle row is reached, by impact `of a pin 20 carried by the lever I1 against a stationary abutment 2 I.

The device as described operates in the following manner: l

Prior to the sinking of a fresh row the deflected jack I is in the position A shown in dotted lines. The spring bar or comb I ll occupies with its springs 9 the upper position C shown in dotted lines in Fig. 1 and in full lines in Fig. 4. Shortly before the slurcock 4 is moved on the first rocker I the spring bar Ill together with the springs 9 is caused to rock to its lower position D (Fig. 5). The slurcock carrier 5 has slidably mounted thereon the roller I8 which travels together the slurcock 4 in. a longitudinal direction shown by the arrow in Fig. 3. During this movement the periphery of the roller I8 slides gradually over the stems of the successive springs 9 in such a way as to raise the latter from their lower positions D to their upper positions C (Fig. 5), in` which the projection 6 of the jack I, which just performs its sinking movement, may freely pass. Due to the movement of the stem of the spring 9 down from the highest point on the periphery of the roller I8 the free end 8 of the spring slides down from its upper position C and over the highest point of the projection 8 onto the upper part of the inclined face 1 of the latter, thus reaching the position E. From this position the free end 8 of the spring 9 begins to slide down the inclined face 1 of the projection 8 to the position F, shown in Fig. 6, immediately before the end of the movement of the jack and sinker to their sinkingposition, this operation taking place in the most 4 steeply inclined face of slurcock 4 (Fig. 2). Due to the spring being lowered to the position F (Fig. 6), the lateral pressure is reduced and the end position oi the jack and sinker after termination of the sinking operation is safely secured. A moment before the deflection of the jack from the position B to position A, the springs 9 are caused to swivel in a manner known per se to their upper position C, so that the projections 6 on the jacks I are kept out of contact with the ends of the springs (Fig. 4).

The invention is not limited to the example described in the specification and shown in the drawing, since it may be applied also to other machines operating under similar` conditions as those set forth herein.

What I claim is;

1. InV a fiat knitting machine of the type de; scribed including a horizontally disposed series of sinkers, a series of upstanding jacks pivoted at th-e lower end and having a sinker engaging upper end adapted to engage and advance' the sinkers to loop-forming position, a slurcock carrier and a slurcock carried thereby for successively engaging and swinging said jacks to sinker advancing position, a. rearwardly extending projection on the back of each of said jacks adjacent the upper sinker engaging end thereof, said projections each having a rearwardly facing inclined camming surface on the free end thereof, a spring bar disposed above the path of movement of the slurcock and in substantial horizontal alignment with the rearwardly extending projections on the backs of said jacks, and forwardly extending substantially horizontal jack spring', one for each jack, carried by said spring bar and having free ends adapted slidingly to'engage the respective rearwardly facing inclined camming surface of the projections on the backs of the jacks upon shifting of the jacks by the slurcock to sinker advancing position to bias and retain the jacks in said position.

2. In a knitting machine according to claim 1, means operating in coordination with the slurcock for successively engaging the jack springs and lifting them from engagement with the projections on the backs of the jacks during the major portion of the motion of the jacks to sinker advancing position.

3. A knitting machine according to claim 2 in which the means for engaging the jack springs comprises a roller carried by the slurcock carrier in position to coordinate the engagement and disengagement of the jacksprings Athereby with the advancement'of the jacks by the slurcock. 4. A knitting machine according to claim 3 in which a switch mounting is provided for the spring engaging roller to position the samei'n correct cooperative relation with either operating face of the slurcock and means is provided for switching the roller mounting at the end of each pass of the slurcock carrier to position the same incorrect operative relation to the operating face of the Slurcock which is the working face forv the next pass. n'

JAROSLAV VACLAVIK.

REFERENCES CITED The following references are of record inthel file of this patent:

UNITED STATES PATENTS 

